LibTest/isolate/ReceivePort/asBroadcastStream_A01_t03.dart

// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/// @assertion Stream<T> asBroadcastStream ({void onListen(StreamSubscription<T>
///   subscription), void onCancel(StreamSubscription<T> subscription)})
/// Returns a multi-subscription stream that produces the same events as this.
/// If this stream is single-subscription, return a new stream that allows multiple subscribers.
/// It will subscribe to this stream when its first subscriber is added,
/// and will stay subscribed until this stream ends, or a callback cancels the subscription.
/// @description Checks that if the only subscription to broadcast stream cancel,
/// broadcast stream unsubscribes from underlying stream.
/// @author ilya
/// @author a.semenov@unipro.ru

import "dart:async";
import "../../../Utils/expect.dart";
import "IsolateStream.dart" as IsolateStream;

var cancelResult;
List receivedData = [];
bool onDoneCalled = false;

void finish() {
  if (cancelResult == null) {
    Expect.listEquals([0], receivedData);
    Expect.isFalse(onDoneCalled);
  }
  asyncEnd();
}

main() {
  asyncStart();

  var s = IsolateStream.fromIterable([0, 1, 2, 3], onDone: finish);
  var b = s.asBroadcastStream();

  StreamSubscription subs = b.listen(null);

  subs.onData((i) {
    receivedData.add(i);
    cancelResult = subs.cancel();
  });

  subs.onDone(() {
    onDoneCalled = true;
  });
}